One of the ways of ridding pools, spas or other bodies of water of harmful organism is to add a halogen such as chlorine or bromine to the body of water. Typically, the halogen may be added to the body of water through a bulk feeder. In the bulk feeder tablets or pucks of chlorine or bromine are placed in a chamber of the bulk feeder where the water flowing through the bulk feeder comes into contact with the halogen located therein. One of the disadvantages of the bulk feeders is that it is difficult to control the level of halogen that is dispersed into the body of water, which often results in over chlorination or over brominating of the body of water. While such bulk feeders are relatively inexpensive the cost of the overuse of chlorine and or bromine in the bulk feeders can quickly negate any benefits of the bulk feeder. To reduce the problem of over chlorination or bromination as well as improving the control of the level of chlorine or bromine in a body of water other types of feeders that separately dispense two different biocides may be used.
One method and apparatus for controlling the harmful organisms in a body of water in a bulk feeder uses two dispensers that deliver two different biocides. Such a device is shown in King U.S. Pat. No. 7,347,935. In this device the two biocides are located in two separate dispensers that are placed in a free or non-fitted condition in the chamber of a bulk feeder. The dispensers are allowed to move about in the chamber in response to the fluid flow through the chamber of the feeder, which enables the water to come into contact with the biocides located therein. As the dispensers move about in the chamber of the feeder the biocides therein are released into the water passing through the chamber of the feeder. In such devices in addition to the control valve on the feeder the dispensers may include adjustable valves on each dispenser in order to better control the dispersant level of each of the biocides.
Another chemical feeder for dispensing two chemicals into a pool is shown in U.S. Pat. No. 5,251,656 where two compartments containing water treatment materials with a venturi housing to draw the water treatment materials out of each of the compartments and into the pool.
U.S. Pat. No. 6,471,858 shows a dispensing apparatus where a pair of cylindrical containers containing water treatment materials are located in a coaxial condition. The containers are cantileverly mounted within a top chamber in a sand filter, which allows the water to flow through both of the containers before flowing through a bed of sand.
Another method and apparatus for accurately delivering two biocides from a single chamber in an inline feeder is shown in King U.S. Pat. Nos. 6,527,952 and 6,190,547. In this device two nestable canisters are concentrically positioned in the chamber of an inline feeder with each of the nestable canisters having inlets and outlets that separate the flow of water into two separate streams with each of the two streams following separate but parallel flow paths through the biocides in their respective nestable canisters.
Since most feeders are integrally mounted in a circulation line of a body of water such as a pool or spa the conversion of a bulk feeder to a cartridge system that can accurately deliver two different biocides becomes costly since one may have to remove and replace the existing bulk feeder with a feeder that provides parallel flow paths through the dispensers therein. In other cases where the dispensers are free to move about the chamber of the feeder the task of control of the delivery rate of the biocides from the separate dispensers becomes more delicate since in addition to adjusting the setting of the control valve of the bulk feeder the valve of one or both of the dispensers may need to be adjusted to control the flow of water through the dispensers and hence the level of biocide that is delivered to the body of water. Thus a need exists for a cartridge system that can be used in prior art bulk feeders to alleviate problems of over halogenation but also provide a system for delivering two or more biocides to the body of water, which for example may be a pool, a spa or the like although the cartridge system may be used with any body of water which requires delivery of a biocide thereto.
In contrast to the prior art the system described herein the invention allows one to provide dispersant control which avoids over halogenation of the body of water in existing bulk feeders and without having to separately adjust gate valves on each of dispensers used in the bulk feeder.